Thanks a lot for all the responses and input. I've enjoyed reading through everyone's thoughts and experiences, especially the bit about the early guild. To try and sum up what has already been said, it seems to me that almost everyone is in consensus that high-casual as a collective term [i]is[/i] advanced by another name, mostly without the stigma usually attached to roleplays devised within the advanced sub-forum. I believe this aptly answered my question as to the classification of high-casual: It's a mini-advanced within the more accessible casual sub-forum.

Also, 

[quote=Mahz]
Blackfire, Hyzhenhok, and I bluffed hard when we wrote the "standards" for Casual and Advanced.We knew we would never enforce them because that's a full-time job. But by using words like "moderated" and "strict", we decided to err on the side of scaring users away and created a mental barrier. [/quote]

Mahz you clever bastard. . .